Sports spread betting began in the United Kingdom in the late 1980s to offer an alternative form of sports wagering to traditional fixed odds, or fixed-risk, betting. With fixed odds betting, a gambler places a fixed-risk stake on stated fractional or decimal odds on the outcome of a sporting event that would give a known return for that outcome occurring or a known loss if that outcome doesn’t occur (the initial stake). With sports spread betting, gamblers are instead betting on whether a specified outcome in a sports event will end up being above or below a ‘spread’ offered by a sports spread betting firm, with profits or losses determined by how much above or below the spread the final outcome finishes at.
Teasers are similar to parlays except the point spread on each game moves a certain number of points in the player's favor. In football the player gets 6 to 7 points, and in basketball, 4 to 5 points. The player pays for this in the form of much lower winnings. For example, if the Vikings were part of a 6-point teaser, then they would only need to win by more than 4 points to cover. If the Rams were part of a teaser, they could win, or lose by less than 16, and cover.
The one variance you might come across in any pointspread listing is the commission owed on a bet. Instead of moving the actual spread for a game, some books will try and direct money one way or the other by adjusting the juice. For example, if there was a (-120) next to the listed pointspread, you would now owe $120 on a losing $100 bet. Sometimes a book will reduce or eliminate the juice all together to move money towards a particular side of a matchup. In this case, you might see (-105) or (+100) next to the pointspread to signify the reduced or zero commission for that bet.